1. Field of the Invention
The present invention relates a scan driver, a light emitting driver, and a driving method thereof. More particularly, the present invention relates to a scan driver, a light emitting driver, and a driving method thereof that are capable of minimizing an influence of a leakage current.
2. Description of the Related Art
Currently, various flat panel displays that can reduce the weight and volume that are drawbacks of the cathode ray tube have been developed. Flat panel displays include a liquid crystal display (LCD), a field emission display, a plasma display panel (PDP), and an organic light emitting diode (OLED) display.
The flat panel display includes a display panel consisting of a plurality of pixels arranged in a matrix format. The display panel includes a plurality of scan lines in a row direction and a plurality of data lines in a column direction, and the plurality of scan lines and the plurality of data lines intersect. The plurality of pixels are driven by scan signals and data signals transmitted through the corresponding scan lines and data lines.
The flat panel display is classified into a passive matrix light emitting display device and an active matrix light emitting display device according to a driving method thereof. Among them, the active matrix type that selectively turns on/off the pixels is mainly used in terms of resolution, contrast, and operation speed.
One pixel of the active matrix organic light emitting diode (OLED) display includes an organic light emitting diode OLED, a driving transistor controlling a current amount supplied to the organic light emitting diode OLED, and a switching transistor transmitting a data signal controlling a light emitting amount of the organic light emitting diode OLED to the driving transistor.
For the light emitting of the organic light emitting diode OLED, the driving transistor must be continuously maintained in a turned-on state. Also, the resistance of the organic light emitting diode OLED may be increased by deterioration. In the case of a panel of a large size, a characteristic deviation between the driving transistors is generated, and the resistance increase by the deterioration of the organic light emitting diode OLED and a moiré pattern due to the characteristic deviation between the driving transistors may be generated. The characteristic deviation of the driving transistor means a deviation of the threshold voltage and mobility between the plurality of driving transistors forming the panel of a large size. Even though the same data voltage is transmitted to the gate electrode of the driving transistor, currents that flow through the driving transistor are different according to the characteristic deviation between a plurality of driving transistors.
To compensate the characteristic deviation between the driving transistors and the resistance deviation by the deterioration of the organic light emitting diode OLED, a determined data signal is periodically or intentionally applied to the pixel and the pixel current of each is measured. Here, the application time of a scan signal applying the data signal to the pixel and a light emitting signal light emitting the pixel is increased. If the application time of the scan signal and the light emitting signal is increased, the scan driver and the light emitting driver may be affected by the leakage current. Accordingly, the voltage of the scan signal and the light emitting signal may not be normally output, and the characteristic deviation between the driving transistors and the resistance deviation due to the deterioration of the organic light emitting diode OLED may not be normally compensated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.